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interphases
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On variations of the interphase thickness and the slope of strengthening by clay addition in exfoliated polymer-clay nanocomposites
, Article Polymer (United Kingdom) ; Volume 90 , 2016 , Pages 302-308 ; 00323861 (ISSN) ; Khederlou, Kh ; Payandehpeyman, J ; Bagheri, R ; Sharif University of Technology
Elsevier Ltd
Abstract
Polymer-clay nanocomposites (PCNs) have received intensive attention in recent years because of their wide domain of applications. The present report provides an approach to calculate the thickness of nanometric interphase region in exfoliated PCNs based on the information about their macroscopic modulus and their nanoclay content. First, the concept of interphase region in PCNs is explained with an “algae explanation”. Then, a series of parametric finite element simulations together with analytical equations are employed to derive an explicit relationship between the interphase thickness and the PCN macroscopic modulus. The obtained analytical model considers the structural impact of the...
Investigating Effects of Interphase on Mechanical Properties of Particulate Metal-Matrix Nanocomposites Using Surface Elasticity
, M.Sc. Thesis Sharif University of Technology ; Naghdabadi, Reza (Supervisor)
Abstract
Due to ignoring the effect of length scale and neglecting the details at nanosize, classical methods are not sufficiently accurate to determine the properties of nanostructured materials. More reliable results can be obtained, using surface elasticity theory. Lots of analytical, experimental and numerical investigations have been done on the effect of interphase on the mechanical properties of polymer nanocomposites whereas metal matrix nanocomposites are in the first stages of analytical and numerical researches and have attracted so much attention.
The main objective of this research is to investigate the effects of interphase as well as coating, on the mechanical behavior of metal...
The main objective of this research is to investigate the effects of interphase as well as coating, on the mechanical behavior of metal...
Contribution of ordered-inordered phenomenon within the interphase region toward increasing elastic modulus in CNT/polymer nanocomposites
, Article Materials Science and Technology Conference and Exhibition 2015, MS and T 2015, 4 October 2015 through 8 October 2015 ; Volume 1 , October , 2015 , Pages 595-602 ; 9781510813939 (ISBN) ; Goodarzi Hosseinabadi, H ; NACE International ; Sharif University of Technology
Association for Iron and Steel Technology, AISTECH
2015
Abstract
Exceptional mechanical properties of carbon nanotubes (CNTs) such as high elastic modulus, stiffness and tensile strength have made them as promising reinforcement in polymer nanocomposite systems. The characteristics of CNTs/polymer interphase region directly affect the efficiency of nanotubes for improving the nanocomposite mechanical properties. In this work, the influence of chains alignment within the interphase region on elastic response of the nanocomposite is assessed using a novel ordered-inordered approach. The applicability of the presented approach is examined by implementing the approach on a series of reported data available in the literature. The effects of CNT content,...
Effective mechanical properties of unidirectional composites in the presence of imperfect interface
, Article Archive of Applied Mechanics ; Vol. 84, issue. 6 , June , 2014 , pp. 807-819 ; Print ISSN: 0939-1533 ; Toozandehjani, H ; Sharif University of Technology
Abstract
In this paper, the equivalent inclusion method is implemented to estimate the effective mechanical properties of unidirectional composites in the presence of an imperfect interface. For this purpose, a representative volume element containing three constituents, a matrix, and interface layer, and a fiber component, is considered. A periodic eigenstrain defined in terms of Fourier series is then employed to homogenize non-dilute multi-phase composites. In order to take into account the interphase imperfection effects on mechanical properties of composites, a stiffness parameter in terms of a matrix and interphase elastic modulus is introduced. Consistency conditions are also modified...
Investigation of the interphase effects on the mechanical behavior of carbon nanotube polymer composites by multiscale modeling
, Article Journal of Applied Polymer Science ; Volume 117, Issue 1 , March , 2010 , Pages 361-367 ; 00218995 (ISSN) ; Naghdabadi, R ; Sharif University of Technology
2010
Abstract
In this article, a multiscale modeling procedure is implemented to study the effect of interphase on the Young's modulus of CNT/polymer composites. For this purpose, a three-phase RVE is introduced which consists of three components, i.e., a carbon nanotube, an interphase layer, and an outer polymer matrix. The nanotube is modeled at the atomistic scale using molecular structural mechanics. Moreover, three-dimensional elements are employed to model the interphase layer and polymer matrix. The nanotube and polymer matrix are assumed to be bonded by van der Waals interactions based on the Lennard-Jones potential at the interface. Using this Molecular Structural Mechanics/Finite Element...
Mechanical properties and structure of solvent processed novolac resin/layered silicate: Development of interphase region
, Article RSC Advances ; Volume 5, Issue 98 , Jun , 2015 , Pages 80875-80883 ; 20462069 (ISSN) ; Shojaei, A ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
Composites of phenol-formaldehyde (PF) resin with Closite Na+ and Closite 30B up to 20 wt% loadings were prepared by solution mixing. Tensile testing showed that both pristine and organically modified clays increased considerably the mechanical properties of PF resin at 2.5 wt% loading followed by marginal improvement or even sacrificed properties at high loadings. DMA and DSC analyses suggested development of a highly crosslinked and well adhered interphase around silicate layers. A novel three-phase model considering the interphase region was proposed to predict composite modulus. The model was successfully employed to correlate morphological characteristics and mechanical properties of...
Enhanced mechanical properties of chitosan/nanodiamond composites by improving interphase using thermal oxidation of nanodiamond
, Article Carbohydrate Polymers ; Volume 167 , 2017 , Pages 219-228 ; 01448617 (ISSN) ; Shojaei, A ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Polymer composite films based on chitosan (CS) and nanodimaond (ND) were prepared using solution casting method. ND with variable contents of carboxylic functional group was prepared using thermal oxidation at temperature of 420 °C under air atmosphere at various durations of 1.5 and 4.5 h. The interfacial interaction between NDs and CS and morphological evolution of CS in presence of NDs were investigated by Fourier transform infrared (FTIR), differential scanning calorimeter (DSC) and X-ray diffraction (XRD) analyses. A significant improvement in tensile strength (∼85%) and tensile modulus (∼125%) of CS was achieved by oxidized ND (OND) obtained at higher oxidation time of 4.5 at low...
A novel lifetime prediction method for lithium-ion batteries in the case of stand-alone renewable energy systems
, Article International Journal of Electrical Power and Energy Systems ; Volume 103 , 2018 , Pages 115-126 ; 01420615 (ISSN) ; Dufo López, R ; Roshandel, R ; Bernal Agustin, J. L ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
This paper presents a mathematical formulation of lithium-ion batteries, including aging and temperature effects. The model is developed by integrating the simplified single particle model (SSPM) and reduced-order model (ROM) to predict solid electrolyte interphase growth (SEI). Results show agreement with the experimental data at 25 °C operating temperature and moderate cycling currents. A maximum error of 3.6% in finding the battery discharged Ah is observed in harsh operating conditions, including 60 °C and approaching the end of life of the battery. Due to the typical operating conditions of stand-alone renewable energy systems, more accurate estimations are expected. Finally, this...
Insights into the efficient roles of solid electrolyte interphase derived from vinylene carbonate additive in rechargeable batteries
, Article Journal of Electroanalytical Chemistry ; Volume 909 , 2022 ; 15726657 (ISSN) ; Sadeghi Malek, S ; Ershadi, M ; Sharifi, H ; Ahmadi Daryakenari, A ; Boorboor Ajdari, F ; Ramakrishna, S ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Formation of unstable solid electrolyte interphase (SEI) layers lacking of thermal stability in non-aqueous electrolytes of rechargeable batteries is the main bottleneck for their long-life cycling, especially at elevated temperatures. Inclusion of a small dose of functional electrolyte additives into the batteries' electrolyte can be highly beneficial to surmount this issue. Of these additives, vinylene carbonate (VC) has drawn particular attention thanks to its high ability to build protective layers at anodes showing good integrity and outstanding thermal stability. In addition to its primary roles in present-day lithium-ion batteries (LIBs), VC additive has also been examined in other...
Cycling performance of LiFePO4/graphite batteries and their degradation mechanism analysis via electrochemical and microscopic techniques
, Article Ionics ; Volume 28, Issue 1 , 2022 , Pages 213-228 ; 09477047 (ISSN) ; Mosallanejad, B ; Mohammadzad, M ; Hosseini Hosseinabad, S. M ; Ramakrishna, S ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
In this work, cycling-induced aging occurring in 18650-type LiFePO4/graphite full cells at different C-rates is studied extensively. The mechanism of performance degradation is investigated using a combination of electrochemical and microstructural analyses. Half-cell studies are carried out after dismantling the full cells, using fresh and cycled LiFePO4 cathode and graphite anode to independently study them. The results show that the capacity of LiFePO4 electrodes is significantly recovered. The rate of capacity fading in the discharge state considered as irreversible capacity in the graphite is higher than LiFePO4 half cells, indicating a greater degradation in the performance of this...
The Effect of Structural Defects of Graphene Reinforced Polymer Nanocomposites on Mechanical Properties
, M.Sc. Thesis Sharif University of Technology ; Naghd Abadi, Reza (Supervisor)
Abstract
Nanocomposites are widely used due to unique properties such as low density and high strength in many industries such as electronics, telecommunications, aerospaces, Petrochemicals and shipbuildings. Meanwhile, due to the importance of economic issues, polymer based nanocomposites are the most used type of nanocomposites. The purpose of this thesis is studing the structural defects of graphene-reinforced nanocomposite polymers on the mechanical properties of these materials. Defects created in nanocomposites can be divided into two categories after construction. The first category is the defects that are created in the graphene structure when it is synthsis, and the second happen at the...
Simple and green oxidation of cyclohexene to adipic acid with an efficient and durable silica-functionalized ammonium tungstate catalyst
, Article Catalysis Communications ; Vol. 43 , 5 January , 2014 , pp. 169-172 ; Mahmoodi Hashemi, M ; Sharif University of Technology
Abstract
A novel silica-functionalized ammonium tungstate interphase catalyst has been reported as a non-nitric acid route for adipic acid production from one-pot oxidative cleavage of 30% hydrogen peroxide and catalytic amounts of p-toluenesulfonic acid (PTSA). The catalyst has been simply prepared by commercially available starting material. The structure of the catalyst has been investigated using FT-IR spectroscopy, atomic absorption, TEM, SEM and XRD analysis. The catalyst has shown good to high activity even up to 10 runs of reaction. Simple preparation of the catalyst, avoids using harmful phase transfer catalyst (PTC) and/or chlorinated additives are among the other benefits of this work
Synthesis of Conductive Magnetite Nanocomposite based on Polyaniline/Poly(maleic acid-co-acrylic acid) with Core-Shell Structure
, Article Advances in Polymer Technology ; 2016 ; 07306679 (ISSN) ; Najafi Moghadam, P ; Mahmoodi Hashemi, M ; Sharif University of Technology
John Wiley and Sons Inc
2016
Abstract
In this study, a new type of magnetite nanocomposite with a core-shell structure was synthesized using Fe3O4 nanoparticles as a core and polyaniline (PANI) as a shell. For this propose, the surface of Fe3O4 was chemically modified with hexamethylenediisocyanate (HMDI) to improve its compatibility and interphase interaction with the polymeric matrix. Thereafter, the PANI was reacted with modified Fe3O4 to anchor them to PANI by covalent bands which acted as a shell. In the second step, the poly (maleic acid-co-acrylic acid) (P(MAc-co-AA)) as polymeric dopant for the PANI was synthesized. Finally, the PANI anchored to Fe3O4 was immersed in an aqueous solution of poly (maleic...
Modeling the interphase region in carbon nanotube-reinforced polymer nanocomposites
, Article Polymer Composites ; 2018 ; 02728397 (ISSN) ; Jam, J. E ; Arab, B ; Firouz-Abadi, R. D ; Sharif University of Technology
John Wiley and Sons Inc
2018
Abstract
Carbon nanotubes are regarded as ideal fillers for polymeric materials due to their excellent mechanical properties. Mechanical analysis without consideration of nanotube–matrix interphase, may not give precise predictions. In this work, the impacts of interphase on the behavior of polymer-based nanocomposites are studied. For this purpose, a closed-form micromechanical interphase model considering the diameter of nanotube, the thickness of interphase, and mechanical properties of nanotube and polymer is proposed to estimate the overall mechanical properties of nanotube-reinforced polymer nanocomposites. Furthermore, the effective elastic constants of the nanocomposites for a wide range of...
Polymer/nanodiamond composites - a comprehensive review from synthesis and fabrication to properties and applications
, Article Advances in Colloid and Interface Science ; Volume 269 , 2019 , Pages 122-151 ; 00018686 (ISSN) ; Salkhi Khasraghi, S ; Hashemi, M ; Rabiei, S ; Shojaei, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Nanodiamond (ND)is an allotrope of carbon nanomaterials which exhibits many outstanding physical, mechanical, thermal, optical and biocompatibility characteristics. Meanwhile, ND particles possess unique spherical shape containing diamond-like structure at the core with graphitic carbon outer shell which intuitively contains many oxygen-containing functional groups at the outer surface. Such superior properties and unique structural morphology of NDs are essentially attractive to develop polymer composites with multifunctional properties. However, despite a long history from the discovery of NDs, which is dated back to the1960s, this nanoparticle has been less explored in the field of...
Modeling the interphase region in carbon nanotube-reinforced polymer nanocomposites
, Article Polymer Composites ; Volume 40, Issue S2 , 2019 , Pages E1219-E1234 ; 02728397 (ISSN) ; Jam, J. E ; Arab, B ; Firouz Abadi, R. D ; Sharif University of Technology
John Wiley and Sons Inc
2019
Abstract
Carbon nanotubes are regarded as ideal fillers for polymeric materials due to their excellent mechanical properties. Mechanical analysis without consideration of nanotube–matrix interphase, may not give precise predictions. In this work, the impacts of interphase on the behavior of polymer-based nanocomposites are studied. For this purpose, a closed-form micromechanical interphase model considering the diameter of nanotube, the thickness of interphase, and mechanical properties of nanotube and polymer is proposed to estimate the overall mechanical properties of nanotube-reinforced polymer nanocomposites. Furthermore, the effective elastic constants of the nanocomposites for a wide range of...
Cycling performance of LiFePO4/graphite batteries and their degradation mechanism analysis via electrochemical and microscopic techniques
, Article Ionics ; 2021 ; 09477047 (ISSN) ; Mosallanejad, B ; Mohammadzad, M ; Hosseini Hosseinabad, S. M ; Ramakrishna, S ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In this work, cycling-induced aging occurring in 18650-type LiFePO4/graphite full cells at different C-rates is studied extensively. The mechanism of performance degradation is investigated using a combination of electrochemical and microstructural analyses. Half-cell studies are carried out after dismantling the full cells, using fresh and cycled LiFePO4 cathode and graphite anode to independently study them. The results show that the capacity of LiFePO4 electrodes is significantly recovered. The rate of capacity fading in the discharge state considered as irreversible capacity in the graphite is higher than LiFePO4 half cells, indicating a greater degradation in the performance of this...
Hierarchical multiscale modeling of nanotube-reinforced polymer composites
, Article International Journal for Multiscale Computational Engineering ; Volume 7, Issue 5 , 2009 , Pages 395-408 ; 15431649 (ISSN) ; Naghdabad, R ; Sharif University of Technology
2009
Abstract
A finite element-based hierarchical multiscale modeling scheme is presented and used for the analysis of nanotube-reinforced polymer composites. The scheme presented here consists of micro- and macroscale boundary value problems linked together using a computational homogenization scheme. Using the presented hierarchical multiscale scheme, we have studied nanotube-reinforced polymer composites, and the elastic properties are determined. Using different representative volume elements (RVEs) representing different volume fractions of aligned nanotubes, the effect of the nanotube volume fraction and the existence of an interphase layer on the effective elastic modulus of the nanocomposite are...
Study of the Surface Effect on the Behavior of a FG Multiphase Nano-sphere with Spherical Anisotropy due to Some Nonuniform Eigenstrain Field
, M.Sc. Thesis Sharif University of Technology ; Mohammadi Shodja, Hossein (Supervisor)
Abstract
The elastic field is one of the challenges in optimizing the lifetime and capacity of the lithiumion batteries. Graphite nanoparticles have been widely used in Li-ion batteries, due to their mechanical, thermal and electrical properties. During the lithiation, chemical reactions occurred in the electrolyte, which forms a solid electrolyte interphase(SEI) in the surrounding of nanoparticles as well as stress fields inside the nanoparticles. Therefore, the purpose of this research is to examine the effects of the surface/interface on diffusion induced stresses(DIS) within core-shell nanosphere due to non-uniform distribution of eigenstrain fields. Due to the mechanical behavior of the phases,...
Study of the Surface Effect on the Behavior of a FG Multiphase Nano-Sphere with Spherical Anisotropy Due to some Nonuniform Eigenstrain Field
, M.Sc. Thesis Sharif University of Technology ; Mohammadi Shodja, Hossein (Supervisor)
Abstract
The elastic field is one of the challenges in optimizing the lifetime and capacity of the lithium-ion batteries. Graphite nanoparticles have been widely used in Li-ion batteries, due to their mechanical, thermal and electrical properties. During the lithiation, chemical reactions occurred in the electrolyte, which forms a solid electrolyte interphase(SEI) in the surrounding of nanoparticles as well as stress fields inside the nanoparticles. Therefore, the purpose of this research is to examine the effects of the surface/interface on diffusion induced stresses(DIS) within core-shell nanosphere due to non-uniform distribution of eigenstrain fields. Due to the mechanical behavior of the phases,...